1. Field of the Invention
The present invention is generally directed to tissue removal devices and, more particularly, to mechanical morcellation devices.
2. Description of the Related Art
During surgical procedures and, more particularly, tissue removal procedures, it is desirable to limit the size of the entry incision to minimize the trauma experienced by the patient. In the past, efforts to minimize entry incision size have generally been limited due to the size of the tissue to be removed and the need for access to the tissue.
However, in modern surgery access to the organ is provided by inserting one or more trocar and cannula to the tissue cite. Thereafter, one or more laparoscopes are used to view the tissue to be removed, and additional port sites are used to gain access to the tissue to sever it from tissue which is to remain. However, the entry incision must still be sized to allow removal of the severed tissue and, therefore, the reduction in entry incision size is rather limited even in more modern or recently developed surgical procedures.
One system which has been developed to overcome this limitation is described in Laparoscopic Nephrectomy: A review of 16 Cases, Surgical Laparoscopy & Endoscopy, Vol. 2, No. 1, pp. 29-34 (Raven Press, Ltd., 1992), the disclosure of which is expressly incorporated herein in its entirety. This publication describes a method for removing renal tissue using a mechanical morcellator. In this method of removal, the kidney and associated renal tissue, after being severed from the ureter, renal arteries, and veins, are placed in an impermeable containment bag. The neck of the bag is closed, withdrawn from a laparoscopic port site, and reopened to gain access to the tissue contained therein. Thereafter, with the tissue remaining in the bag within the patient's body, a morcellator cutting head is introduced into the bag and activated, fragmenting and aspirating the renal tissue. The aspirated tissue is retained within a filtering chamber within the morcellator handle, which must be cleaned following the surgical procedure.
Although the morcellation device and method disclosed in this reference represents an improvement over tissue removal methods which require a large entry incision, several undesirable structural and operational features remain.
The morcellation techniques known in the art do not provide a cover for the cutting head or allow relative extension and retraction of the cutting head. Also, the known morcellators do not provide means, whether electrical or mechanical, to prevent the accidental or unintentional actuation of the morcellator cutting head. Moreover, the known morcellators are not ergonomically designed, and are rather bulky and cumbersome in use. These undesirable features cooperate to create a mechanical morcellator which is susceptible to accidental or unintentional actuation.
Therefore, there exists a need in the art for an effective mechanical morcellator which provides a relatively movable cutting head and which includes means to prevent the unintentional actuation of the morcellator cutting head. There also exists a need for a mechanical morcellator which aspirates fragmented tissue to an exterior retention means and for a morcellator satisfying the deficiencies in the prior art which is ergonomically designed to make handling and use thereof more convenient for the surgeon.